--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/cubicweb/devtools/test/unittest_fill.py	Sat Jan 16 13:48:51 2016 +0100
@@ -0,0 +1,70 @@
+# copyright 2003-2010 LOGILAB S.A. (Paris, FRANCE), all rights reserved.
+# contact http://www.logilab.fr/ -- mailto:contact@logilab.fr
+#
+# This file is part of CubicWeb.
+#
+# CubicWeb is free software: you can redistribute it and/or modify it under the
+# terms of the GNU Lesser General Public License as published by the Free
+# Software Foundation, either version 2.1 of the License, or (at your option)
+# any later version.
+#
+# CubicWeb is distributed in the hope that it will be useful, but WITHOUT
+# ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
+# FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public License for more
+# details.
+#
+# You should have received a copy of the GNU Lesser General Public License along
+# with CubicWeb.  If not, see <http://www.gnu.org/licenses/>.
+"""unit tests for cubicweb.devtools.fill module
+
+"""
+import re
+
+from logilab.common.testlib import TestCase, unittest_main
+
+from cubicweb.devtools.fill import ValueGenerator, _ValueGenerator
+
+ISODATE_SRE = re.compile('(?P<year>\d{4})-(?P<month>\d{2})-(?P<day>\d{2})$')
+
+
+class AutoExtendableTC(TestCase):
+
+    def setUp(self):
+        self.attrvalues = dir(_ValueGenerator)
+
+    def tearDown(self):
+        attrvalues = set(dir(_ValueGenerator))
+        for attrname in attrvalues - set(self.attrvalues):
+            delattr(_ValueGenerator, attrname)
+
+
+    def test_autoextend(self):
+        self.assertNotIn('generate_server', dir(ValueGenerator))
+        class MyValueGenerator(ValueGenerator):
+            def generate_server(self, index):
+                return attrname
+        self.assertIn('generate_server', dir(ValueGenerator))
+
+
+    def test_bad_signature_detection(self):
+        self.assertNotIn('generate_server', dir(ValueGenerator))
+        try:
+            class MyValueGenerator(ValueGenerator):
+                def generate_server(self):
+                    pass
+        except TypeError:
+            self.assertNotIn('generate_server', dir(ValueGenerator))
+        else:
+            self.fail('TypeError not raised')
+
+
+    def test_signature_extension(self):
+        self.assertNotIn('generate_server', dir(ValueGenerator))
+        class MyValueGenerator(ValueGenerator):
+            def generate_server(self, index, foo):
+                pass
+        self.assertIn('generate_server', dir(ValueGenerator))
+
+
+if __name__ == '__main__':
+    unittest_main()